PSI - Issue 28

I S Nikitin et al. / Procedia Structural Integrity 28 (2020) 2032–2042 Author name / Structural Integrity Procedia 00 (2019) 000–000

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a)

b)

max ( ) N  for V-notched specimen:  - real test points,  - calculating points.

Fig. 4. Fatigue curves

4.2. Double criterion model A series of numerical experiments were conducted to determine the impact of the proposed double criterion scheme on fatigue behavior of a specimen. We studied a multi-axial case namely a torsion-compression stress-state.

Fig. 5. Specimen geometry

All tests were conducted on a holed specimen, Fig. 5. Width at boundaries W 0 = 107 mm, main width W = 60 mm, height H = 170 mm, hole diameter D = 30 mm, thickness T = 1.75 mm. It should be noted that the numerical experiments were performed in three-dimensional space. Due to symmetry of the specimen over Ox axis we decided to perform calculations only on the top half of the specimen. At that part the finite element grid is shown. We applied deformations at the top boundary of the specimen; due to its symmetry quasi-same deformations but in the opposite direction were applied at the bottom boundary, so at